Cleaning and Flushing of Piping Systems ME- Building Group

SECTION 15961 - CLEANING AND FLUSHING OF PIPING SYSTEMS

PART 1 - GENERAL

0.1 SUMMARY

A. Provide complete cleaning and flushing consisting of all materials, equipment, labor, services, and tests necessary to completely clean all piping before installation and to flush all piping and systems after installation.

B. Provide all equipment, material, labor and testing required to properly pacify hydronic system piping so that it may be integrated into the existing hydronic system with no adverse affects or contamination.

C. Provide all equipment, material, labor and testing required for proper disinfection of city water piping.

0.2 WORK NOT INCLUDED

A. Pressure testing shall be as specified in Division 15 “Testing of Piping Systems.”

PART 2 - PRODUCTS

0.1 MATERIALS

A. Detergents, solvents, and other cleaning agents shall be compatible with materials of fabrication of systems where they are used. No cleaning agent shall adversely affect materials or mechanisms in systems and cleaning agents shall be acceptable to equipment manufacturers and the plant environmental coordinator.

B. Detergents, solvents, and other cleaning agents shall be compatible with process streams to be handled by systems in which the cleaning agents are used.

C. Owner will provide water for pipe cleaning and flushing. Other cleaning fluids, agents, and equipment shall be provided by Contractor.

D. Hydronic systems shall use the following products or an equal substitute and shall be approved by the Plant environmental coordinator prior to flush. 1. Ferroquest FQ7103: Use prior to any other for the removal of iron oxides from the metal surfaces, and passivation of the base metal. a. A 3 percent Ferrroquest concentration is recommended for the removal of deposits. Ferroquest shall be circulated until a steady iron concentration is reached in the circulating water. As the Ferrroquest dissolves iron oxide deposits, ferric hydroxide is formed and the pH rises it is necessary to maintain a pH range of 6.5 to 7.5, therefore, supplemental feeding of our Ferroquest FQ7102 Neutralizer may be required in extremely dirty systems. 2. CorrShield MD409, Corrosion Protection: Shall be placed in the pacified pipe after the system has been cleaned and flushed. 3. Provide all necessary temporary equipment required for cleaning and flushing operations. Page 1 of 5 Revision Date: 12/14/04 Project & Bid Package File name: 080e623df07396b8cdacc4db6c0233df.doc

E. Provide temporary/permanent hose connections for supply, discharge and recirculating lines for the new piping system.

F. Provide temporary hoses or piping at the ends of the main and branch lines of the piping system as required to accomplish flush of the piping.

G. Provide a temporary pump of sufficient head and GPM required to achieve a flushing velocity of at least 6 feet per second.

H. Provide temporary chemical skids with tote tanks as required for mixing chemicals and serving as a source reservoir and/or collection point for cleaning and flushing solutions.

I. Provide temporary bag filters (with filter bags) as required for removal of contaminants from flushing process.

J. Provide all hose, electrical leads and supply connections for completion of system required to fill, drain and refill of the lines utilizing plant supplied water and power.

PART 3 - EXECUTION

0.1 PREINSTALLATION CLEANING

A. Before installation, piping, unless otherwise specified, shall be cleaned as follows: 1. Hammer, brush, scrub with soapy rags, etc. to loosen sand, dirt, or scale when necessary. Remove excess grease and oil from exterior surface. 2. Blow with air, or flush with clean water, and inspect before erection. 3. Pipe cleaned and stored before installation shall be dried and ends sealed with a rigid plug or flange protector and tape.

B. Physical cleaning procedures shall not damage materials or mar surfaces of such materials. Hammering shall not be used on cast iron, fiberglass-reinforced plastic, or plastic pipe.

0.2 PRIOR TO FLUSHING

A. Removals 1. Remove orifice plates, traps, strainer elements, flow control valves, etc. prior to or during process of cleaning. Remove instruments which might be damaged by cleaning procedures. All such items shall be replaced with spool pieces, plugs, or blind flanges. A "blind list" shall be prepared listing where blinds have been installed for cleaning and shall be provided to Owner after cleaning is complete to verify that all blinds have been removed. 2. Items removed from piping system shall be cleaned separately. 3. Valves shall be blocked in open position. 4. New gaskets, thread lubricants, etc. shall be used when removed items are reinstalled after cleaning.

B. Temporary Bypass Piping: Provide full size bypass piping and valves at coils and heat exchangers such that the coils and heat exchangers can be isolated.

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C. Temporary Strainers: Disconnect piping to be flushed from equipment or install temporary strainers immediately upstream of such equipment.

D. System Protection 1. Protect piping and equipment against overpressure, collapse from vacuum, and hydraulic shock during flushing and draining procedures. 2. Exercise special care with polyvinyl chloride (PVC) and fiberglass-reinforced plastic (FRP) piping and upon initial filling of long pipe runs to determine that pipe is in contact with hangers and supports before filling. Piping bowed out of hangers or supports will settle or lengthen during filling and resulting forces may be damaging at changes in direction. 3. Install high point vents and low point drains required to remove trapped air and to drain flushing liquid.

0.3 HYDRONIC SYSTEM PIPING FLUSHING

A. By its design, hydronic systems have a supply and return and therefore are best flushed by recirculation. This method works well for the mains and large branches, but smaller branches require flushed flow out of the system without return. The process of pacifying the piping after flushing however is best accomplished with all branch supply and return piping in its normal in- service flow configuration.

B. Isolate the new piping from the existing system using valves and blind flanges. Each of the connection points should have fill/drain piping, valves and connection points should be installed off the bottom of elevated pipe. The piping should also have vent valves at the high points of the piping and on all high points of isolated legs of branch piping. 1. Note: Care should be taken during installation of both temporary flush and permanent components, to assure that they are free of debris, oil and other potential contamination.

C. Install temporary drain piping and/or hoses to drain locations as required or collect the water in a portable tote tank for transfer to the proper disposal location. Coordinate disposal of all flushing an pacifying water with the plant environmental coordinator. 1. Note: This water typically needs to be sent to the plant waste treatment system not to the sanitary sewer.

D. Install temporary fill connection and start filling the piping, venting continuously until the system has been completely filled and as much air as possible has been eliminated from the system.

E. The chemical supplier should start chemical injection through the temporary chemical tote until the predetermined concentration of chemical (if required) has been achieved.

F. Flush through the piping mains from the extreme end to extreme end of the system until solution is well mixed and stable. Recirculate the water through the piping system until the desired cleanliness has been achieved. If the water is very dirty and the tote tank does not provide enough settling time to remove the debris prior to being suctioned out by the Contractor provided recirculation pumps, install a temporary bag housing with a filter or wire mesh strainer in the flowpath.

G. After the mains have been flushed, flush all of the branch lines starting with the branch closest to the supply point and progress toward the extreme end of the piping that is furthest from the

source. Repeat the flushing through each branch until the desired cleanliness has been achieved.

H. Collect water samples and label them with a location and time/date, for analysis of cleanliness. Continue to sample the new piping system piping until it is completely flushed clean of all contaminants and matches the influent source for cleanliness.

I. When desired cleanliness has been achieved, all flushing water should be drained from the system and then refilled, circulated throughout the mains and branches to rinse out the flushing chemicals, and dumped again.

J. Restore all piping to its design state (remove all temporary piping and close all valves), and refill the system with water and the proper amount of pacifying chemical as directed by the chemical supplier. Recirculate the chemicals throughout the system for a sufficient amount of time as the chemical supplier requires for proper mixing and metal exposure. 1. Note: The pacifying period may require 24 to 72 hours.

K. Drain the system, refill with water and coordinate with the Owner to open the new piping to the existing hydronic system for final mixing of Owners chemical into the newly refilled piping via the existing system pumps and chemical injection system.

L. In the event that the new piping is not to be integrated into the existing hydronic system for more than a month, coordinate with the Owner as to whether the system is to remain in “wet layup” with the pacifying chemicals in place or “dry layup” in which case the piping is to be drained and a nitrogen purge applied 1. Drain the system and refill with water and Owner furnished chemicals as directed by the Owner. 2. Process Fluids piping shall be placed in “dry layup” as specified.

0.4 POTABLE WATER PIPING DISINFECTION

A. New or repaired potable water systems shall be disinfected in accordance with the method prescribed by the local health authority or, in the absence of a prescribed method, in accordance with either AWWA C651 or AWWA C652 or per the 1997 International Plumbing Code as described below. This requirement shall apply to “on-site” or “in-plant” fabrication of a system or to a modular portion of a system.

B. The piping system shall be flushed with clean, potable water until dirty water does not appear at any of the points of outlet. Coordinate disposal of all flushing and disinfecting water with the plant environmental coordinator. (Note: Initial flush water typically needs to be sent to the plant waste treatment system and the disinfecting water to the sanitary sewer.) Install temporary hoses as required to reach existing disposal points, or collect the water in a portable tote tank for transfer to the proper disposal location.

C. The piping shall be filled with a water/chlorine solution containing at least 50 parts per million (50mg/L) of chlorine, and the piping shall be valved off and allowed to stand for 24 hours; or the piping shall be filled with a water/chlorine solution containing at least 200 parts per million (50mg/L) of chlorine, and allowed to stand for 3 hours.

D. Following the required standing time, the piping shall be flushed with clean potable water until the chlorine is purged from all parts of the system piping.

E. The procedure shall be repeated where shown by a bacteriological examination that contamination remains present in the system.

0.5 COMPRESSED AIR PIPING CLEANING

A. Coordinate use of the existing plant compressed air system or provide air compressors as directed by the Owner, for blowing down the newly installed compressed air piping. Do not interfere with Plant operations.

B. Determine portions of the main piping runs that can be isolated and blown down separately from the branches and isolate the branch outlets.

C. Connect appropriately sized temporary steel bag filter housing with bag filter or fine mesh screen at the end of the blowdown opening. In addition, provide a temporary silencer for these openings.

D. Open and close the isolation valves outlet valves for a brief period with a dirty filter and then repeat with clean filters (or clean the wire mesh screen between blowdowns) until sufficiently clean as determined by the Owners representative.

E. Repeat the procedure for each portion of the main runs and for each of the separate branches.

0.6 NATURAL GAS PIPING CLEANING

A. Contractor shall comply with local gas company standards for cleaning natural gas piping systems.

END OF SECTION